House Crook is infamous for its centuries-old practice of burning their enemies alive as sacrifice to the Lord of Light, to the point that they used a burnt man as their House sigil. The Crooks are one of the only, if not the only house that worships the Lord of Light instead of the Faith of the Seven like the rest of the Westerland Houses. The Crooks supposedly gave up this practice after bending the knee to House Lannister, and centuries later Lord Tywin Lannister outlawed sacrificial burning in the Westerlands altogether, but the Crooks continued their practice. This resulted in them being despised by a majority of the Westerland Houses.
House Crook's heraldry consists of a crisped burnt man surrounded by two fiery red hearts of the Lord of Light. Their official motto is "One God, One Goal, One Light", though a common saying of members of the House is "The night is dark and full of terrors".
The origins of House Crook date back to at least the Age of Heroes, a savage age in which the houses of the First Men waged war upon one the other. For centuries, House Crook resisted the efforts of the Casterlys and the Lannisters to unify the Westerlands under their rule, killing several Lannisters and Casterlys in the process, and, according to rumors, keeping their burned and crisped bodies as trophies and hanging them above the gates of the Hearthfire.
Eventually, the Crooks were defeated and bent the knee to House Lannister, giving up their practice of burning their prisoners to the Lord of Light as sign of their submission. Nevertheless, they remained the second most powerful house of the Westerlands. The practice of sacrificial burning, however, was officially outlawed in the Westerlands just during the lordship of Tywin Lannister.
The Crooks are one of the fighting forces at the Battle of Stone Mill.